Abstract

Adenine phosphoribosyltransferase (APRT) is a relatively non-abundant soluble enzyme which in man is coded for by a single structural gene on chromosome 16 (1). A partial deficiency of APRT in man was first described in 1968 (2). These subjects were asymptomatic and were shown to be heterozygous for the enzyme defect. A complete deficiency of APRT activity has now been described in several patients with renal calculi composed of 2,8-dihydroxyadenine who are homozygous for the enzyme defect (reviewed in ref. 3). The genetic mechanisms responsible for an inherited deficiency of APRT however have remained undefined.